1) Field of the Invention
The present invention relates to non-motorized pedal powered scooters, and more particularly, to a lever drive system for a scooter using an arrangement of cams operatively associated with a pair of crank arms for controlling upward and downward movement of the crank arms.
2) Description of Related Art
The prior art replete with various types of non-motorized scooters. One type of scooter involves the use of lever type crank arms on which the user stands. A reciprocating up and down movement of the crank arms turns a sprocket through any series of various connections. The sprocket drives a chain operatively associated with a sprocket on a drive wheel. A problem arises, however, in that the lever type crank arms do not include any mechanisms to control the up and down movement. As such, the lever type crank arms can be hard to depress and get started when first getting on the scooter and they also tend to end a downward stroke with a sudden stop, providing a harsh operating feeling for the user. In some arrangements, the crank arms operate independently and thus a downward movement of one crank arm has no operating effect on helping to move the second crank arm.
Accordingly, it is an object of the present invention to provide a drive system for a pedal operated scooter that incorporates an arrangement of cams to control the upward and downward movement of the crank arms.
It is a further object of the present invention to provide a cam arrangement in which the downward movement of a given crank arm is decelerated as it approached the bottom of a stroke.
It is a further object of the present invention to provide a cam arrangement in which a downward movement of one crank arm facilitates an upward movement of a second crank arm.